Many epoxy based composites used for structural applications in the aerospace industry are composed of toughened epoxy resins. Epoxy monomers containing aromatic moieties tend to have a greater melt viscosity than the alkoxy based monomers. In addition, epoxy resins composed of solely aromatic epoxy tend to be glassy whereas the flexible alkoxy based epoxy resins tend to be rubbery. Such resins typically exhibit sub-optimal mechanical properties relative to the glassy resins, for example, lower yield stress.
Dispersing an organically modified layered silicate clay in a polymeric matrix to form a nanocomposite may improve the resulting material's mechanical properties including increasing yield stress. However, when such a clay is added to a polymeric matrix, the resulting material may lose properties in other areas such as a decrease in glass transition temperature Tg and reduced ductility and toughness.